Dry-state biological sample storage and preservation is desired for various applications, such as analyte detection, sensing, forensic and diagnostic applications, genome sequencing, whole-genome amplification, and the like. Long-term storage, transport and archiving of bio-specimens on filter paper and other chemically modified matrices are well-known techniques for preserving different biomolecules, such as nucleic acids, peptides, and proteins for different downstream applications.
Existing methods for the extraction of biomolecules from a substrate generally employ the use of different types of aqueous and organic extraction solvents, which may have adverse effects on biomolecule stability or downstream usability. Methods are known for using temperature and pH for differential binding and selective release of biomolecules, such as nucleic acids, from a solid substrate, for example, by binding of nucleic acids at acidic pH and release at alkaline pH. Alternatively, very high temperature or alkaline pH or combinations of both may be used to release bound biomolecules from a substrate through denaturation. The mixed mode resins are also known for recovering a target compound from aqueous solution at high or low ionic strength, using change in pH. The use of extremes of various environmental factors, such as pH, temperature, and/or high salt concentrations for re-dissolving or eluting nucleic acids may cause nucleic acids, especially RNA, to denature or degrade. Other environmental factors, such as, pressure, chemical or enzymatic hydrolysis, or the presence of contaminants may also promote the degradation of archived biomolecules such as DNA, RNA, or proteins during collection and storage.
Furthermore, known techniques for eluting of biomolecules from solid substrates may result in comparatively low recovery. For example, the recovery of purified nucleic acids from solid substrates may be low or inefficient as determined by quantitative real time polymerase chain reaction (PCR). The success of the downstream applications of isolated nucleic acids from a sample may also depend on maintaining the integral structure and function of target biomolecules and the amount of biomolecules used for each application.
Accordingly, a simplified method and an appropriate solid substrate for collecting, storing and eluting biomolecules from a sample disposed on the substrate with greater recovery is needed. In addition, maintaining the structural and functional integrity of the eluted nucleic acids is highly desirable.